Enossal single tooth implant

ABSTRACT

Enossal tooth implant for firmly seating dental prostheses has an  essentiy cylindrical base member, which is introducible into a bore introduced in a jaw bone and has a blind bore open toward its coronal end, a spacer sleeve which has an inside bore, is emplaceable on a coronal face edge of the base member and has an arrangement for a twist-resistant fastening to the base member, and has a fastening head for a dental prosthesis and an implant post which is introducible through the inside bore into the blind bore and connectable to the base member. The fastening head is formed by a coronal, hollow end region of the spacer sleeve and the implant post is received in this hollow end region leaving a space for receiving an inset nut which is provided with a threaded bore extending perpendicular to the longitudinal center axis of the spacer sleeve and which is aligned with an opening in a circumferential wall of the spacer sleeve so that a securing screw can penetrate through the opening and be threaded into the threaded bore of the inset nut for securing the dental prosthesis.

BACKGROUND OF THE INVENTION

The invention is directed to an enossal single tooth implant for afirmly seated dental prosthesis, having an essentially cylindrical basemember introducible into a bore introduced into a jaw bone, said basemember comprising a blind bore open toward its coronal or outer end,having a spacer sleeve emplaceable on the coronal or outer face edge ofthe base member, an implant post introducible into the blind bore andconnectable to the base member, said implant post penetrating an insidebore of the spacer sleeve, which has a connecting means for thetwist-resistant fastening of the spacer sleeve on the base member and afastening head for the dental prosthesis.

German Patent Application 195 09 762.9-32 discloses the improvement of adental implant according to German Letters Patent 40 28 855, whereby theimplant post, which also serves therein as retainer screw for the spacersleeve relative to the base member, comprises the fastening head for thefirmly seated dental prosthesis at its coronal end, said fastening headprojecting beyond the spacer sleeve. For example, the dental prosthesisis either glued to the fastening head or is connected thereto bycementing.

When the species-defining single tooth implant of German PatentApplication 195 09 762.9-32 is modified to the effect that the implantpost ends coronally at a distance from the coronal face edge within theinside bore of the spacer sleeve, whereby the coronal end region of thespacer sleeve itself then forms the fastening head for the dentalprosthesis, then the dental prosthesis can in fact likewise be attachedto the spacer sleeve with a glued or cemented connection. However, thereare difficulties in securing the framing or structure of the dentalprosthesis with a securing screw that preferably proceeds perpendicularto the longitudinal center axis of the spacer sleeve in thoseapplications wherein a screwed connection is desired between the framingof the dental prosthesis and the fastening head.

This difficulty is based on the fact that the circumferential wall ofthe spacer sleeve is so thin that the required forces for fastening thedental prosthesis cannot be exerted with a securing screw of theabove-described type without inappropriate deformation of the spacersleeve walls.

SUMMARY OF THE INVENTION

The invention is based on the object of further-improving the singletooth implant of the species to the effect that a screwed connection isenabled between the dental prosthesis and the fastening head withoutdeformation of the walls of the spacer sleeve.

This object is inventively achieved in that the fastening head is formedby a coronal, hollow end region of the spacer sleeve; in that thecoronal end of the implant post is cervically arranged under the endregion; and that an inset nut provided with a threaded bore proceedingperpendicular to the longitudinal center axis of the spacer sleeve isarranged in the end region, and a securing screw will penetrate anopening provided in the circumferential wall of the end region and isscrewable into said inset nut for securing the dental prosthesis.

It can thereby be provided that the circumferential wall of the spacersleeve is fashioned tapering frustum-like in coronal direction in theend region.

The invention also potentially provides that the implant post can bescrewed into an inside bore of the implant upon anti-twist engagement ofinterlocking tongues of the spacer sleeve with complementaryinterlocking elements of the base member.

According to a first embodiment of the invention, the inset nut isfashioned of one piece with a clevis-type web or pin that is to be putin place on the coronal face edge of the circumferential wall of thespacer sleeve.

It is provided according to a second embodiment that recesses which arepositioned opposite one another are provided in the coronal face edge ofthe spacer sleeve, and a clevis-like web or pin which is fashioned ofone piece with the inset nut is received in these recesses. An extremelyexact positioning of the inset nut relative to the spacer sleeve ispossible when the clevis-type web rests play-free in the recesses.

It can thereby be provided that the recesses are arranged such thattheir common center axis proceeds perpendicular to the symmetry axis ofthe opening that is provided in the circumferential wall of the spacersleeve.

The clevis-like pin or web of the inset nut should then also be arrangedto proceed perpendicular to the symmetry axis of the threaded bore.

At its end facing toward the clevis-like pin or web, the inset nutpreferably has an outside diameter, at least in regions, that, forenabling a friction lock between the inset nut and spacer sleeve, isslightly larger than the inside diameter of the inside bore of thespacer sleeve in the corresponding region an inserted inset nut. Here,too, the inset nut can be reliably positioned with reference to thespacer sleeve.

It can thereby be provided that the inset nut has its end facing towardthe clevis-like pin or web provided with projections that, residingopposite one another, are provided at both sides of the clevis-type web,whereby the outside contour of the projections defines the regions oflarger outside diameter.

The invention is based on the surprising perception that one succeeds inassuring a faultless screwed connection between the dental prosthesisand the coronal end region of the spacer sleeve fashioned as fasteninghead in that an inset nut is hooked into the spacer sleeve. This insetnut will accept the securing screw proceeding transversely to thelongitudinal center axis of the spacer sleeve, so that thecircumferential wall of the spacer sleeve need not absorb any pressureforces.

Further features and advantages of the invention derive from thefollowing description in which exemplary embodiments are explained onthe basis of the schematic drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial cross-sectional view through the longitudinal centeraxis with portions in elevation of a spacer sleeve of a first exemplaryembodiment of the enossal single tooth implant of the invention;

FIG. 2 is a plan view onto the spacer sleeve according to FIG. 1;

FIG. 3 is a side view with portions broken away of a spacer sleeve of asecond exemplary embodiment;

FIG. 4 is a plan view of the spacer sleeve according to FIG. 3;

FIG. 5 is a cross-sectional view of a spacer sleeve of a third exemplaryembodiment of the enossal single tooth implant of the invention;

FIG. 6 is a perspective view of an inset nut for employment given thesingle tooth implant of FIG. 5; and

FIG. 7 is a second cross-sectional view of the coronal end of the singletooth implant of the invention taken on a plane extending perpendicularto the plane of FIGS. 1, 3 and 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

At their cervical end, which is the lower end in the drawing, the spacersleeves 14 shown in FIGS. 1, 3 and FIG. 5 comprise a plurality ofinterlocking tongues 16 that adjoin a centering collar 18 that is offsetby a shoulder 20 relative to the region 22 of the spacer sleeve 14adjoining the cervical end of the spacer sleeve in coronal direction. Inthe way disclosed in German Patent Application 195 09 762.9-32, thespacer sleeve 14 is introducible into a base member (not shown) that hasbeen fixed into the jaw of the patient and has its coronal end providedwith interlocking elements corresponding to the interlocking tongues 16,so that the spacer sleeve 14 can be connected to the base member in ananti-twist fashion. Upon inter-engagement of the interlocking tongues 16with the corresponding interlocking elements of the base member, thespacer sleeve 14 is firmly connectable in an anti-twist fashion to thelatter with an implant post fashioned as a retainer screw that can bescrewed into an inside bore of the base member.

FIGS. 1, 3 and 5 also show that the spacer sleeve 14, following afastening region 24 in which an inside bore of the cervically andcoronally open spacer sleeve 14 has a diameter that corresponds to thatof the implant post (not shown), coronally comprises an end region 24 inwhich an inside bore 26 (FIGS. 1 and 5) has a larger diameter than theinside bore 25 in the area of the fastening region 22. Theaforementioned retainer head of the implant post engages a shoulder 27between the bores 25 and 26, which shoulder 27 lies close to that end ofthe fastening region 24 lying at the bottom in the drawing (FIGS. 1 and5), so that, thus, the inside bore 26 is fashioned coronally hollowfollowing the retainer head of the implant post.

As FIGS. 1, 3 and 5 also show, the outside of the end region 24 of thespacer sleeve is provided with an attachment shoulder 28, as disclosedin detail in terms of function and purpose in the above-cited GermanPatent Application 195 09 672.9-32, which is referenced in this respectfor further explanation.

In the end region 24, a circumferential wall 30 of the spacer sleeve 14comprises a coronally tapering frustum shape.

FIG. 1 shows how close to the coronal face edge of the end region 24 ofthe spacer sleeve 14 an inset nut 34 is hooked into the inside bore 26thereof with a clevis-type pin or web 32 put in place on the coronalface edge of the circumferential wall. This inset nut 34 is fashionedsolid except for a threaded bore 36 proceeding perpendicular to thelongitudinal center axis of the spacer sleeve 14. A securing screw 38 isscrewed into the threaded bore 36. This securing screw 38 has a screwhead 40 and will penetrate an opening 42 provided in the circumferentialwall 30 after the threaded bore 36 has been aligned with the opening 42before the securing screw 38 is screwed in. The relative positioning ofsecuring screw 38 and spacer sleeve 14 is shown especially clearly inFIG. 2.

The alignment is facilitated when, as shown FIGS. 3 and 4, recesses 44,46 that reside opposite one another on a common center axis 48 areprovided in the coronal face edge of the spacer sleeve 14. Theclevis-type web (not shown in FIG. 3) is received into these recesses44, 46. A corresponding dimensioning of the recesses 44, 46 makes itpossible that the clevis-type web rests essentially free of playtherein. Flattened portions 50, 52 that serve for the application of atool or for the alignment of the dental prosthesis or, respectively, theframing thereof are formed in the circumferential wall 30 under therecesses 44, 46. These flattened portions also serve for formation of acement bar when putting the crown of the tooth in place.

The enossal single tooth implant shown in FIG. 5 comprises an inset nut34 whose end facing toward the clevis-type web 32 comprises twoprojections 62, 68, which are fashioned by grooves or spaces 64 and 66and are integral with the inset nut 34. The outside contour of theprojections 62, 68 is dimensioned such that the outside diameter of theinset nut 34 is slightly enlarged in the region of the projections 62and 68 in comparison to the inside diameter of the inside bore 26 of thespacer sleeve 14. In the seating region of the projections 62, 68against the inside wall of the inside bore 26, the projections 62, 68therefore exert a force directed toward the circumferential wall 30 thatholds the inset nut 34 in a friction lock therewith. The projections 62and 68 can thereby yield into the spaces 64 and 66 that are formedbetween the projections 62, 68 and the clevis-type web 32. The inset nut34 can thus be positioned in the inside bore 26 so that the threadedbore 36 is aligned with the opening 42 for the securing screw 38. Nodislocation of the inset nut 34 in the bore 26 need be feared when thesecuring screw 38 is screwed in.

FIG. 6 shows the inset nut 34 in a perspective view. Circular segment-shaped projections are provided at both sides of the clevis-like web orpin 32 of the inset nut 34 with only the projection 62 being shown inFIG. 6. The section length of a projection 62 approximately correspondsto the inside diameter of the threaded bore 36. A free space 64 remainsbetween the projection 62 and the clevis-type web 32.

In a longitudinal sectional view, FIG. 7 shows how the inset nut 34 liesin the inside bore 26 of the spacer sleeve. In the embodiment of thesingle tooth implant according to FIG. 5 or, respectively, FIG. 6, thediameter of the inset nut is not enlarged compared to the insidediameter of the inside bore 26. It can be especially clearly seen fromthe illustration of FIG. 7 that the web 32 and threaded bore 36 lieperpendicular to one another in their symmetry axes, so that apre-positioning of the inset nut 34 can easily occur.

Just like the implant post and the inset nut 34, which is fashioned ofone piece with the clevis-type web 32, the spacer sleeve is composed ofa titanium alloy or the like.

The described arrangement makes it possible to secure the dentalprosthesis or, respectively, the framing thereof with the securing screw38 at the end region of the spacer sleeve 14, which simultaneously formsthe fastening head for the firmly seated dental prosthesis (not shown).In a way familiar to a person skilled in the art, such a screwedconnection exhibits considerable advantages over a glued connection.

Both individually as well as in arbitrary combination, the features ofthe invention disclosed in the above description, in the drawing as wellas in the claims can be critical for realizing the invention.

We claim:
 1. Enossal single tooth implant for a firmly seated dentalprosthesis, said implant having an essentially cylindrical base memberintroducible into a bore introduced into a jaw bone, said base membercomprising a blind bore open toward its coronal end, said implant havinga spacer sleeve emplaceable on the coronal face edge of the base member,an implant post introducible into the blind bore and connectable to thebase member, said implant post penetrating an inside bore of the spacersleeve, which has a connecting means for the twist-resistant fasteningof the spacer sleeve on the base member and said implant having afastening head for the dental prosthesis, the improvement comprising thefastening head being formed by a coronal, hollow end region of thespacer sleeve; a coronal end of the implant post being cervicallyarranged under the end region; and an inset nut being provided with athreaded bore proceeding perpendicular to the longitudinal center axisof the spacer sleeve being arranged in the end region, a securing screwpenetrating an opening provided in a circumferential wall of the endregion and being screwable into said inset nut for securing the dentalprosthesis.
 2. Single tooth implant according to claim 1, wherein thecircumferential wall of the spacer sleeve is fashioned taperingfrustum-shape in a coronal direction in the end region.
 3. Single toothimplant according to claim 1, wherein the implant post can be screwedinto an inside bore of the implant upon anti-twist engagement ofinterlocking tongues of the spacer sleeve with interlocking elements ofthe base member complementary thereto.
 4. Single tooth implant accordingto claim 1, wherein the inset nut is a one-piece member with aclevis-type web that is to be put in place on a coronal face edge of thecircumferential wall of the spacer sleeve.
 5. Single tooth implantaccording to claim 1, which includes recesses residing opposite oneanother being provided in a coronal face edge of the spacer sleeve, aclevis-type web integral with the inset nut being received in saidrecesses.
 6. Single tooth implant according to claim 5, wherein therecesses are arranged such that their common center axis proceedsperpendicular to the symmetry axis of the opening that is provided inthe circumferential wall of the spacer sleeve.
 7. Single tooth implantaccording to claim 1, which includes a clevis-type web of the inset nutbeing arranged to extend perpendicular to the symmetry axis of thethreaded bore.
 8. Single tooth implant according to claim 7, wherein theinset nut adjacent the end with the clevis-type web has at least regionswith an outside diameter slightly larger than an inside diameter of theinside bore of the spacer sleeve to form a frictional lock between thenut and spacer sleeve.
 9. Single tooth implant according to claim 8,wherein the inset nut has its end facing toward the web provided withprojections that, residing opposite one another, are provided at bothsides of the clevis-type web, the outside contour of the projectionsforming the regions of larger outside diameter.
 10. Single tooth implantaccording to claim 1, wherein the spacer sleeve has a circumferentialwall with an outer end face with a pair of recesses opposite oneanother, said inset nut being a one-piece member having a clevis-typeweb at an end, said clevis-like web being received in said recesses whenthe nut is inserted into the hollow end region.